1. Field of the Invention
The present invention generally relates to wet-type image forming devices and to electrophotographic apparatuses. More specifically, the present invention relates to a wet-type image forming device which employs electrophotography to render visible, using a liquid developer, an electrostatic latent image formed on a photoreceptor, and to an electrophotographic apparatus incorporating the wet-type image forming device.
2. Description of the Related Art
FIG. 1 shows a schematic sectional view of a conventional wet-type image forming device 100a. During image formation, within non-discharged areas, which were not exposed to light, of a photoreceptor belt B, a potential difference between the photoreceptor belt B and a development roller 1 generates an electric field having an opposite direction as in discharged areas, which were exposed to light, of the photoreceptor belt B. Accordingly, a reverse development occurs; i.e., toner particles T' adhere to the development roller 1. Consequently, problems may arise in the course of subsequent image forming operations such as the image density becoming too high, and a constant gap not being maintained between the photoreceptor belt B and the development roller 1. Thus, the development roller 1 is cleaned using a potential difference between the development roller 1 and a cleaning roller 3.
Also, toner particles T' adhere to a squeeze roller 2 when excess liquid developer T is squeezed off from a developed image formed on the photoreceptor belt B. Consequently, problems may arise in the course of subsequent image forming operations such as the photoreceptor belt B becoming stained as the squeeze roller 2 continues to rotate, and the ability to squeeze off excess liquid developer T being progressively diminished. Thus, the squeeze roller 2 is cleaned using a potential difference between the squeeze roller 2 and the cleaning roller 3.
Due to the cleaning of the development roller 1 and the cleaning of the squeeze roller 2, the cleaning roller itself picks up toner particles T'. As the cleaning roller 3 picks up more toner particles T', the potential differences tend to become insufficient for cleaning between the development roller 1 and the cleaning roller 3, and between the squeeze roller 2 and the cleaning roller 3. Thus, the cleaning roller 3 itself is also cleaned.
In the conventional wet-type image forming device 100a, the cleaning roller 3 has been cleaned by opposing rotation of the cleaning roller 3 and a brush roller 5a in contact therewith, and by a cleaning blade 4 contacting the cleaning roller 3. That is, the cleaning of the cleaning roller 3 has been performed by mechanical force alone.
The mechanical cleaning, however, has not been sufficient to fully remove the toner particles T' from the cleaning roller 3. Therefore, the conventional wet-type image forming device 100a has been susceptible to a subsequent problem that the development roller 1 and the squeeze roller 2 are not adequately cleaned.
Furthermore, the conventional wet-type image forming device 100a has not been capable of removing toner particles T' adhering to the brush roller 5a. Therefore, the conventional wet-type image forming device 100a has also been disadvantageous in that the toner particles T' accumulate on the brush roller 5a, reducing the ability to remove toner particles T' from the cleaning roller 3 and the cleaning blade 4.